Berlin 2001 – scientific programme

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P: Plasmaphysik

P 11: Dusty Plasmas and Low Temperature Discharges (Poster Session)

P 11.19: Poster

Thursday, April 5, 2001, 12:30–15:00, AT2

Mass Spectrometric Investigations on a High Pressure Discharge — •Marco Redwitz, Jens Luhmann, and Jürgen Mentel — Ruhr University of Bochum, Fundamentals of Electrical Engineering Group, Universitätsstr. 150, 44780 Bochum, Germany

For several years a model lamp has been used to investigate electrodes for high-pressure low-current gas discharge lamps. The model lamp’s modular design permits variation to parameters such as gas, pressure, arc current as well as material and shape of electrodes used in the discharge.

Different methods are used for preparing and cleaning the parts of the model lamp which are in direct contact with the plasma. Therefore a clean inert-gas atmosphere like in real HID-lamps can be obtained in the discharge tube.

To evaluate the different cleaning methods the composition of the gas in the discharge tube is investigated. A capillary is attached to the discharge tube to take samples of the gas. Using a mass spectrometer a continuous quantitative analysis of these samples is performed during lamp operation. As the results show the cleaning method used does in fact influence the gas composition and thus the lamp properties.

Financial support supplied by the German Federal Ministry of Education and Research, Ref.-No. 13N7763.